Air curtain system for an open-front refrigerated case with dual temperature zones

Abstract

An open-front refrigerated display case is provided having a medium temperature zone disposed above a low temperature zone in a generally vertically-stacked arrangement. A spillover airflow-diverting device is disposed between the medium temperature zone and the low temperature zone and is configured to direct spillover air from the medium temperature zone air curtain (and ambient air entrained therewith) in a direction away from the open front of the low temperature zone. The spillover airflow-diverting device may include louvers configured to direct a gravity-induced flow of the spillover air in an outward direction away from the open front of the low temperature zone, or may include fans to collect spillover air and forcibly direct it in an outward direction away from the open front of the low temperature zone. The outwardly directed spillover air may be discharged in the form of an ‘outer layer’ for an air curtain on the low temperature zone.

What is claimed is: 
     
       1. An open-front refrigerated display case, having a medium temperature zone disposed above a low temperature zone in a generally vertically-stacked arrangement, comprising:
 a medium temperature-controlled space having a medium temperature air curtain arranged to flow across the open front of the medium temperature controlled space; 
 a first fan configured to draw at least a portion of the air from the medium temperature air curtain through a first intake and across a medium temperature cooling coil and through a medium temperature flow path for discharge through a first outlet to maintain operation of the medium temperature air curtain; 
 a low temperature-controlled space having a low temperature air curtain arranged to flow across the open front of the lower temperature-controlled space; 
 a spillover airflow-diverting device disposed between the medium temperature zone and the low temperature zone, the spillover airflow-diverting device configured to direct spillover air from the medium temperature air curtain in a direction away from the open front of the low temperature zone; 
 wherein the spillover airflow-diverting device comprises at least one louver configured to direct a gravity-induced flow of the spillover air in an outward direction away from the open front of the low temperature zone. 
 
     
     
       2. The open-front refrigerated display case of  claim 1 , wherein the spillover airflow-diverting device includes one or more fans configured to collect spillover air from the medium temperature air curtain and direct it in an outward direction away from the open front of the low temperature zone. 
     
     
       3. The open-front refrigerated display case of  claim 1 , wherein the spillover airflow-diverting device includes one or more fans configured to collect spillover air from the medium temperature air curtain and direct it over the open front of the low temperature zone as an outer layer air curtain. 
     
     
       4. The open-front refrigerated display case of  claim 1 , wherein the spillover airflow-diverting device includes one or more fans configured to collect the spillover air from the medium temperature air curtain and direct it across the medium temperature cooling coil and through the medium temperature flow path for discharge through the first outlet to recycle the spillover air and maintain operation of the medium temperature air curtain. 
     
     
       5. The open-front refrigerated display case of  claim 4 , wherein spillover airflow diverting device further comprises a damper configured to direct the spillover air between a first flow path for recycling the spillover air to the medium temperature air curtain and a second flow path for discharging the spillover air as the outer layer air curtain over the open front of the low temperature zone. 
     
     
       6. An open-front refrigerated display case, having a medium temperature zone disposed above a low temperature zone in a generally vertically-stacked arrangement, comprising:
 a medium temperature-controlled space having a medium temperature air curtain arranged to flow across the open front of the medium temperature controlled space; 
 a first fan configured to draw at least a portion of the air from the medium temperature air curtain through a first intake and across a medium temperature cooling coil and through a medium temperature flow path for discharge through a first outlet to maintain operation of the medium temperature air curtain; 
 a low temperature-controlled space having a low temperature air curtain arranged to flow across the open front of the lower temperature-controlled space; 
 a spillover airflow-diverting device disposed between the medium temperature zone and the low temperature zone, the spillover airflow-diverting device configured to direct spillover air from the medium temperature air curtain in a direction away from the open front of the low temperature zone; 
 wherein the spillover airflow diverting device further comprises a damper configured to direct the spillover air between a first flow path for recycling the spillover air to the medium temperature air curtain and a second flow path for discharging the spillover air as at least a portion of the outer layer air curtain of the low temperature zone. 
 
     
     
       7. The open-front refrigerated display case of  claim 6 , wherein the spillover airflow-diverting device further comprises louvers configured to direct a gravity-induced flow of the spillover air in an outward direction away from the open front of the low temperature zone. 
     
     
       8. The open-front refrigerated display case of  claim 6 , wherein the spillover airflow-diverting device includes one or more fans configured to collect spillover air from the medium temperature air curtain and direct it in an outward direction away from the open front of the low temperature zone. 
     
     
       9. The open-front refrigerated display case of  claim 6 , wherein the spillover airflow-diverting device includes one or more fans configured to collect spillover air from the medium temperature air curtain and direct it over the open front of the low temperature zone as an outer layer air curtain. 
     
     
       10. The open-front refrigerated display case of  claim 6 , wherein the spillover airflow-diverting device includes one or more fans configured to collect the spillover air from the medium temperature air curtain and direct it across the medium temperature cooling coil and through the medium temperature flow path for discharge through the first outlet to recycle the spillover air and maintain operation of the medium temperature air curtain. 
     
     
       11. A method of making an open-front refrigerated display case, having a medium temperature zone disposed above a low temperature zone in a generally vertically-stacked arrangement, the method comprising:
 providing a medium temperature-controlled space having a medium temperature air curtain arranged to flow across the open front of the medium temperature controlled space; 
 providing a first fan configured to draw at least a portion of the air from the medium temperature air curtain through a first intake and across a medium temperature cooling coil and through a medium temperature flow path for discharge through a first outlet to maintain operation of the medium temperature air curtain; 
 providing a low temperature-controlled space having a low temperature air curtain arranged to flow across the open front of the lower temperature-controlled space; 
 providing a spillover airflow-diverting device disposed between the medium temperature zone and the low temperature zone, the spillover airflow-diverting device configured to direct spillover air from the medium temperature air curtain in a direction away from the open front of the low temperature zone, wherein the spillover airflow-diverting device comprises at least one of (a) louvers configured to direct a gravity-induced flow of the spillover air in an outward direction away from the open front of the low temperature zone, and (b) a damper configured to direct the spillover air between a first flow path to the medium temperature air curtain and a second flow path that is at least one of (a) over the open front of the low temperature zone, and (b) away from the low temperature zone. 
 
     
     
       12. The method of  claim 11 , wherein the spillover airflow-diverting device includes one or more fans configured to collect spillover air from the medium temperature air curtain and direct it in an outward direction away from the open front of the low temperature zone. 
     
     
       13. The method of  claim 11 , wherein the spillover airflow-diverting device includes one or more fans configured to collect spillover air from the medium temperature air curtain and direct it over the open front of the low temperature zone as an outer layer air curtain. 
     
     
       14. The method of  claim 11 , wherein the spillover airflow-diverting device includes one or more fans configured to collect the spillover air from the medium temperature air curtain and direct it across the medium temperature cooling coil and through the medium temperature flow path for discharge through the first outlet to recycle the spillover air and maintain operation of the medium temperature air curtain.